1. Field of the Invention
The present invention relates to a semiconductor device obtained by mounting a semiconductor chip on a silicon submount, a semiconductor module, and a method of manufacturing the semiconductor module.
2. Description of Related Art
Up to now, large liquid crystal display panels have been applied to a liquid crystal display, a liquid crystal display television, or the like. In many cases, a cold-cathode tube has been used as a backlight of the display panel. In recent years, the use of the cold-cathode tube made of mercury has been avoided in order to overcome so-called RoHS for environmental protection. In addition, one of the most important technical problem of the liquid crystal display panel is how to improve a brightness of an image. From this viewpoint, in the case of using the cold-cathode tube, a color reproduction range is narrow. In particular, a green reproductivity is insufficient. Thus, the use of the cold-cathode tube is avoided.
The use of a backlight device as a substitute for the cold-cathode tube has been under study. As a backlight device example, there is a semiconductor light-emitting device mounted on a silicon submount through flip-chip bonding (for example, see Japanese Unexamined Patent Publication No. 2003-21839). In such semiconductor light-emitting devices, no hazardous material such as mercury is used, and the color reproduction range can be widened.
Further, a semiconductor module as shown in FIG. 16 has been hitherto reported (for example, see Japanese Unexamined Patent Publication No. 2004-253328). As shown in FIG. 16, a power supply voltage is applied to a first electric circuit 101 and a second electric circuit 102. A third LED-connecting electric circuit 103 is inserted between the first electric circuit 101 and the second electric circuit 102. The insulating connecting members 104 extend in the width direction and are arranged away from each other in the longitudinal direction to connect the electric circuits 101, 102, and 103. Each LED 105 is attached to each connecting member 104, and an electric connecting terminal thereof is connected with the third electric circuit 103. The electric circuits 101, 102, and 103 can be manufactured by pressing a long conductor plate such as a copper plate. Further, the connecting member 104 can be formed by insert-molding a resin material.
In the semiconductor module as disclosed in Japanese Unexamined Patent Publication No. 2004-253328, the resin-made connecting members 104 are provided at some intervals in the long electric circuits 101, 102, and 103 made up of a copper plate or the like. Hence, exposed portions of the electric circuits 101, 102, and 103 can be readily deformed, and the entire module can be processed into a desired shape. Further, since the electric circuits 101, 102, and 103 made up of the copper plate or the like are partially exposed, a heat radiation property is high, and the LEDs 105 can be prevented from being damaged due to an excessive temperature rise.
Incidentally, the LED consumes a large amount of power and thus generates a large quantity of heat. Therefore, it is necessary to take an adequate measure for heat radiation to bring this kind of semiconductor light-emitting device into practical use.
In the technique as disclosed in Japanese Unexamined Patent Publication No. 2003-21839, a heat radiating block is placed on the rear surface of the silicon submount. Thus, a measure for heat radiation is taken for the LED. However, any special measure for heat radiation is not taken as for the upper surface of the silicon submount (LED mounting surface). In this regard, there is still room for improvement. That is, the temperature of the upper surface of the silicon submount as the LED mounting surface becomes highest. Thus, it is most rational to take the measure for heat radiation for the upper surface of the LED from the viewpoint of preventing the LED from overheating. In the conventional techniques, the heat radiating block is placed only on the rear surface of the silicon submount. Any special measure for heat radiation is taken for the upper surface of the silicon submount. Accordingly, heat generated in the silicon submount cannot be efficiently released. Moreover, there is a possibility that various problems resulting from the LED overheating, for example, deteriorations in characteristics occur.
In the semiconductor module as disclosed in Japanese Unexamined Patent Publication No. 2004-253328, the electric circuits 101, 102, and 103 are manufactured by pressing copper plate or the like. At the same time, the connecting member 104 is formed by insert-molding a resin. Further, it is necessary to remove a branch that temporarily blocks a path between the electric circuits 101, 102, and 103. This causes a problem in that a manufacturing process becomes completed and the module costs high. Further, in the semiconductor module as disclosed in Japanese Unexamined Patent Publication No. 2004-253328, the exposed portions of the electric circuits 101, 102, and 103 made up of a copper plate or the like are plastic-deformed to thereby process the entire module into a desired shape. This structure has a limitation on flexibility, and thus has a problem in that its application range is narrowed.